Golf balls having multi-layer cores are well known. Also known are particular multi-layer cores having a thermoset center, thermoplastic intermediate core layer, and thermoset outer core layer, such as those disclosed in U.S. Pat. No. 7,708,656 and U.S. Pat. No. 8,262,511.
Golf balls comprising a layer formed from a plasticized polyurethane composition are also known. For example, U.S. Pat. Nos. 6,849,675 and 7,053,142 disclose a golf ball core or cover layer formed from a plasticized polyurethane composition comprising at least one polyurethane and at least one plasticizer.
The present invention provides a novel multi-layer golf ball construction wherein a plasticized polyurethane composition is used to form a core layer in a multi-layer core construction.